Abstract: One variation of an upgrade kit—for an ignition key corresponding to a vehicle and including an immobilizer transponder and a keyless entry transmitter—includes: a wireless jammer configured to interfere with wireless transmission from the immobilizer transponder; a wireless receiver configured to receive an unlock request from an external device; a relay configured to actuate the keyless entry transmitter to unlock a door of the vehicle in response to the unlock request; and an enclosure configured to contain the wireless receiver and a portion of the ignition key.

Abstract: One variation of a method for renting a vehicle includes: receiving a signal from a fleet manager, the signal specifying a current availability of the vehicle for rent; updating a visual indicator arranged on the vehicle according to the signal, the visual indicator visually detectable from outside the vehicle; receiving identification information of a user proximal the vehicle; enabling access to the vehicle for the user in response to verification of the user as a driver of the vehicle; determining, through a sensor arranged within the vehicle, that the user is seated in a driver's seat within the vehicle; and enabling ignition of the vehicle for the user in response to determination that the user is seated in the driver's seat.